Reliability of new radiographic measurement techniques for elbow bony impingement

Background Identifying the location and scale of radiographic changes in elbow bony impingement (EBI) is critical in formulating an appropriate diagnosis and treatment plan for such patients. The purpose of present study was to evaluate the intra-rater and inter-rater reliability of the new radiographic parameters, Anterior Impingement angle (AIa) and Posterior Impingement angle (PIa), for EBI. In addition, to determine if there was a relationship between radiographic parameters and clinical evaluation. Patients and methods Three raters of different levels of training evaluated the radiographs of 60 patients (30 in EBI group and 30 in normal group) twice, at least 2 weeks apart. Intra-rater and inter-rater reliabilities were calculated by Intraclass Correlation Coefficients (ICC) with 95% confidence intervals. Correlation between radiographic parameters and clinical evaluation was calculated by Pearson correlation coefficient. Results In both groups, intra-rater and inter-rater reliabilities were substantial. There were no significant differences in reliability between upper-hand expert surgeons and resident for either measurement. Good correlation was observed between impingement arcs and range of motion values. Conclusions Both AIa and PIa measurements demonstrated substantial intra-rater and inter-rater reliability for normal radiographs and in EBI patients. Good reliability, for either expert surgeons or residents in training, and good correlation between radiographic measurements and manual testing, appoints this method may be easily and reliably used in every day practice.

The standing T1–L1 pelvic angle: a useful radiographic predictor of proximal junctional kyphosis in adult spinal deformity

OBJECTIVE Proximal junctional kyphosis (PJK), which can worsen a patient’s quality of life, is a common complication following the surgical treatment of adult spinal deformity (ASD). Although various radiographic parameters have been proposed to predict the occurrence of PJK, the optimal method has not been established. The present study aimed to investigate the usefulness of the T1–L1 pelvic angle in the standing position (standing TLPA) for predicting the occurrence of PJK. METHODS The authors retrospectively extracted data for patients with ASD who underwent minimum 5-level fusion to the pelvis with upper instrumented vertebra between T8 and L1. In the present study, PJK was defined as ≥ 10° progression of the proximal junctional angle or reoperation due to progressive kyphosis during 1 year of follow-up. The following parameters were analyzed on whole-spine standing radiographs: the T1–pelvic angle, conventional thoracic kyphosis (TK; T4–12), whole-thoracic TK (T1–12), and the standing TLPA (defined as the angle formed by lines extending from the center of T1 and L1 to the femoral head axis). A logistic regression analysis and a receiver operating characteristic curve analysis were performed. RESULTS A total of 50 patients with ASD were enrolled (84% female; mean age 74.4 years). PJK occurred in 19 (38%) patients. Preoperatively, the PJK group showed significantly greater T1–pelvic angle (49.2° vs 34.4°), conventional TK (26.6° vs 17.6°), and standing-TLPA (30.0° vs 14.9°) values in comparison to the non-PJK group. There was no significant difference in the whole-thoracic TK between the two groups. A multivariate analysis showed that the standing TLPA and whole-thoracic TK were independent predictors of PJK. The standing TLPA had better accuracy than whole-thoracic TK (AUC 0.86 vs 0.64, p = 0.03). The optimal cutoff value of the standing TLPA was 23.0° (sensitivity 0.79, specificity 0.74). Using this cutoff value, the standing TLPA was the best predictor of PJK (OR 8.4, 95% CI 1.8–39, p = 0.007). CONCLUSIONS The preoperative standing TLPA was more closely associated with the occurrence of PJK than other radiographic parameters. These results suggest that this easily measured parameter is useful for the prediction of PJK.

Efficacy and radiographic analysis of oblique lumbar interbody fusion in treating adult spinal deformity

Adult spinal deformity (ASD) is usually rigid and requires a combined anterior–posterior approach for deformity correction. Anterior lumbar interbody fusion (ALIF) allows direct access to the disc space and placement of a large interbody graft. A larger interbody graft facilitates correction of ASD. However, an anterior approach carries significant risks. Lateral lumbar interbody fusion (LLIF) through a minimally invasive approach has recently been used for ASD. The present study was performed to evaluate the effectiveness of oblique lumbar interbody fusion (OLIF) in the treatment of ASD. We performed a retrospective study utilizing the data of 74 patients with ASD. The inclusion criteria were lumbar coronal Cobb angle > 20°, pelvic incidence (PI)–lumbar lordosis (LL) mismatch > 10°, and minimum follow–up of 2 years. Patients were divided into two groups: ALIF combined with posterior spinal fixation (ALIF+PSF) (n = 38) and OLIF combined with posterior spinal fixation (OLIF+PSF) (n = 36). The perioperative spinal deformity radiographic parameters, complications, and health-related quality of life (HRQoL) outcomes were assessed and compared between the two groups. The preoperative sagittal vertical axis (SVA), LL, PI–LL mismatch, and lumbar Cobb angles were similar between the two groups. Patients in the OLIF+PSF group had a slightly higher mean number of interbody fusion levels than those in the ALIF+PSF group. At the final follow–up, all radiographic parameters and HRQoL scores were similar between the two groups. However, the rates of perioperative complications were higher in the ALIF+PSF than OLIF+PSF group. The ALIF+PSF and OLIF+PSF groups showed similar radiographic and HRQoL outcomes. These observations suggest that OLIF is a safe and reliable surgical treatment option for ASD.